The present invention relates to mechanized sweeper vehicles that carry one or more gutter broom assemblies each having a rotatable gutter broom for sweeping debris from a pavement toward a pick-up head (in a vacuum or regenerative sweeper) or toward a primary broom (in a mechanized broom sweeper) to sweep debris from pavements and roadways and, more particularly, to a gutter broom positioning-system for reliably and repeatedly positioning a gutter broom at anyone of a plurality of operator selectable positions.
Pavement sweepers of the type used to sweep municipal streets typically include rotatable circular side brooms that are designed to engage the roadway or pavement at the intersection of the pavement and the curbstone, i.e., the gutter. The sweepers typically include a gutter broom mounted on each side of the vehicle; the brooms are motor-driven to brush any accumulated dust/debris into the path of a primary vacuum intake hood, in the case of vacuum regenerative sweepers, or into the path of a primary brush, in the case of mechanized broom sweepers, to move the debris into a containment bin or hopper.
FIG. 1 presents a top view of a generic sweeper vehicle 10 travelling in the direction indicated by the arrow 10-1. The vehicle 10 is equipped with two gutter brooms 12-1 and 12-2 which extend from the underside of the chassis. In FIG. 1, the broken vertical lines P1, P2, and P3, on the driver side of the vehicle 10 are representative of a plurality of possible positions Pn that the gutter broom 12-1 can extend to laterally from the driver side of the vehicle 10. In a similar manner, the broken vertical lines P1, P2, and P3, on the passenger side of the vehicle 10 are also representative of a plurality of possible positions Pn that the gutter broom 12-2 can extend to laterally from the passenger side of the vehicle 10. The three positions shown in FIG. 1, P1, P2, and P3, are merely representative of a much larger number of possible positions Pn. In FIG. 1, the gutter brooms 12-1 and 12-2 are shown at different positions to indicate independent control of each gutter broom; in practice, a sweeper vehicle 10 will generally use only one gutter broom at a time to sweep a single gutter.
It is desirable to have a measure of repeatability in extending a gutter broom to a specific position to optimize the sweeping efficiency for a particular gutter; in general, the vehicle operator will use in-cab controls to extend a gutter broom with the operating position based on operator skill. An attempt, has been made to automate gutter broom positioning to allow more precision in the process, as presented in U.S. Pat. No. 8,136,193 issued Mar. 20, 2012 and assigned to Federal Signal Corp. in the '193 patent, various sensors detect the broom position angle and other angular values and store those values in a memory. Thus, the operator can recall a particular set of data from the memory and set a gutter broom to those values. The system presented in the '193 is relatively expensive and is vulnerable, as are all sensor-dependent control-systems in harsh environments, to sensor reliability and repeatability issues.